Stability Testing; Stability Testing Mhp13/35; Introduction; Equipment - Snorkel MHP1335 Repair Parts Manual

Stability Testing MHP13/35

Introduction

The purpose of this test is to assess if the MHP
1335 meets the requirements of AS 1418-10 2004
Appendix G Stability Calculations. The situation
for minimum stability is with the booms at maximum
outreach over the drawbar, with the maximum
rated load in the platform, a manual force pulling
toward the drawbar and maximum wind load acting
on the back of the machine.
Since this testing involves taking the machine to
the edge of its stability envelope care must be
taken to ensure the test is failsafe i.e. the machine
can not tip over if it fails the test. To this end the
rated load is to be hung from the Test Weight
Harness and the test weight is suspended 200mm
above the ground during the test. If the machine
starts to tip over the test weight will contact the
ground, reducing the overturning moment, so that
the machine can not continue to tip over.

Equipment

MHP 13/35
Spirit level
Rope
Pulley
Test weights & harness
Ratchet tie down

Setup and Procedure

The Test Weight harness location is at the rear
edge of the platform. The test load for a standard
machine is 239kg and the test load for a machine
with an optional basket rotator is 217kg.
The manual force is 400N with an additional
multiplication factor of 1.1 giving 440N or 44.8kg.
The line of action of this force is such that it
produces the greatest overturning moment. That is
the line of action of the force is perpendicular to a
line joining the top rail of the platform to the tipping
line (see Figure 1).
The wind load is assumed to act at the centre of
area of the elevated components. The Wind Load
is 336N at 5.54m above ground. The overturning
moment from the wind is used to find an equivalent
force along the line of action of the manual force.
The calculated force due to wind is 248N or 25.3kg
The load simulating the wind and manual force is
therefore 70.1kg.
MHP13/35 & MHP15/44 V3 – 13619-2
The test procedure is as follows (Refer Figure 1).
1. Set a pulley with rope, 5.985m above the
ground on a fixed pole.
2. Place the machine so that the drawbar is
pointing towards the fixed pole. The centre
of the slew bearing must be 7m from a point
directly beneath the pulley.
3. Raise the machine on the stabilisers to
maximum height.
4. Level the machine laterally using the spirit
level.
5. Level the machine fore and aft such that it is
0.5 deg drawbar down from level. (This
simulates a poor setup by the end user).
6. Slew the booms until the rear of the basket is
pointing towards the pole.
7. Tie the rope from the pulley around the top
rail of the platform on the basket centre line.
8. Attach the Test Weight Harness and the Test
Weight to the platform.
9. Raise the booms to maximum outreach
(lower boom fully up and top boom and jib
boomhorizontal). The "Test load" must be
between 100 and 200mm above ground.
10. Attach a ratchet tie down to the rope coming
from pulley. Attach the other end to the
"Load simulating the wind and manual force".
11. Raise the "Load simulating the wind and
manual force" with the ratchet tie down until
the load is between 100 and 200mm above
the ground. Ensure that the loads are not
swinging i.e. the loads are static. (If both
'rear' legs lift clear of the ground STOP the
test and release the ratchet).

Pass Criteria

The machine can be assessed as meeting the
requirements of AS 1418-10 2004 Appendix G
Stability Calculations if the "Test Load" and the
"Load simulating the wind and manual force" can
be raised clear of the ground simultaneously while
maintaining at least 3 point contact i.e. not more
than 1 stabiliser foot off the ground.
Rev B

Stability Testing

page 17